Electric field dependence of thermal conductivity of a granular superconductor: Giant field-induced effects predicted

The temperature and electric field dependence of electronic contribution to the thermal conductivity (TC) of a granular superconductor is considered within a 3D model of inductive Josephson junction arrays. In addition to a low-temperature maximum of zero-field TC K(T,0) (controlled by mutual inductance L_0 and normal state resistivity R_n), the model predicts two major effects in applied electric field: (i) decrease of the linear TC, and (ii) giant enhancement of the nonlinear (i.e., grad T-dependent) TC with [K(T,E)-K(T,0)]/K(T,0) reaching 500% for parallel electric fields E=E_T (E_T=S_0|grad T| is an "intrinsic" thermoelectric field). A possiblity of experimental observation of the predicted effects in granular superconductors is discussed.Comment: 5 LaTeX pages (jetpl.sty included), 2 EPS figures. To be published in JETP Letter

Electrical conductivity and magnetic properties of La1-xCaxMn1-yFeyO3 Ceramic Samples (x= 0.67, y= 0, 0.05)

The temperature dependence of the electrical resistivity in the range of the charge-ordered phase conforms to the variable-range hopping model. The behavior of the electrical resistivity is governed by the complex structure of the density of localized states near the Fermi levelyesBelgorod State Universit

Prognostic value of changes in arterial stiffness in men with coronary artery disease

Iana A Orlova, Eradzh Yu Nuraliev, Elena B Yarovaya, Fail T AgeevOutpatient department, Russian Cardiology Research Center, Moscow, Russian Federation Background: Men with coronary artery disease (CAD) have been shown to have enhanced arterial stiffness. Arterial function may change over time according to treatment, but the prognostic value of these changes has not been investigated.Objectives: The aim of the present study was to assess whether an improvement in large artery rigidity in response to treatment, could predict a more favorable prognosis in a population of men with CAD.Methods: A total of 161 men with CAD (mean age 56.8 ± 10.9 years) being treated with conventional therapy underwent brachial-ankle pulse wave velocity (PWVba) measurements at baseline and after six months. Follow-up period was 3.5 years. End-points were major adverse cardiac events (MACE): acute myocardial infarction, unstable angina, coronary intervention, or cardiac death.Results: During the three-year follow-up period (since initial six-month follow-up), 30 patients experienced MACE. After six-month follow-up, PWVba had not improved (∆PWVba ≥ 0%, relative to baseline) in 85 (52.8%) of 161 men (Group 1), whereas it had improved (∆PWVba < 0%) in the remaining 76 men (47.2%) (Group 2). During follow-up, we noticed 24 cardiovascular events in Group 1 and six events in Group 2 (P < 0.001). Cox proportional hazards analyses demonstrated that independent of conventional risk factor changes, absence of PWVba decrease was a predictor of MACE (RR 3.99; 95% CI:1.81–8.78; P = 0.004). The sensitivity of ∆PWVba was 80% and its specificity was 54%.Conclusions: This study demonstrates that an improvement in arterial stiffness may be obtained after six months of conventional therapy and clearly identifies patients who have a more favorable prognosis.Keywords: arterial stiffness, coronary artery disease, prognosi

The study of the effect of aluminum powders dispersion on the oxidation and kinetic characteristics

Differential-scanning calorimetry (DSC) and thermogravimetric analysis (TG) were used to study micro-sized aluminum powder ASD-4 and nano-sized powder Alex. The dependence of the oxidation process on the dispersion of the sample particles is shown. The influence of thermogravimetric conditions on the thermal regime of the process was considered, and its kinetic parameters were determined. Calculations of the activation energy and the pre-exponential factor were carried out

Structure of a bacterial type IV secretion core complex at subnanometre resolution

Type IV secretion (T4S) systems are able to transport DNAs and/or proteins through the membranes of bacteria. They form large multiprotein complexes consisting of 12 proteins termed VirB1-11 and VirD4. VirB7, 9 and 10 assemble into a 1.07 MegaDalton membrane-spanning core complex (CC), around which all other components assemble. This complex is made of two parts, the O-layer inserted in the outer membrane and the I-layer inserted in the inner membrane. While the structure of the O-layer has been solved by X-ray crystallography, there is no detailed structural information on the I-layer. Using high-resolution cryo-electron microscopy and molecular modelling combined with biochemical approaches, we determined the I-layer structure and located its various components in the electron density. Our results provide new structural insights on the CC, from which the essential features of T4S system mechanisms can be derived

THE PROBLEM OF OPTIMIZATION OF EXPENSES OF AN ENTERPRISE IN CRISIS CONDITIONS

The article examines the main factors that influencе on the costs of enterprise. Various types of classification of expense are analyzed: internal and external, planned and accidental, primary and secondary. A comprehensive approach to the analysis of the possibility of reducing the costs for cost of goods describes

THE PROBLEM OF OPTIMIZATION OF EXPENSES OF AN ENTERPRISE IN CRISIS CONDITIONS

The article examines the main factors that influencе on the costs of enterprise. Various types of classification of expense are analyzed: internal and external, planned and accidental, primary and secondary. A comprehensive approach to the analysis of the possibility of reducing the costs for cost of goods describes

The formation of strategies for effective management of business environment of the region

This study is aimed to explore the opportunities of creating conditions which is necessary for successful development of small and medium enterprises of Russia and the Belgorod region in particular in the chemical industry of leather and footwear sector. The system of criteria for the assessment of the entrepreneurial activity of small and medium enterprises is proposed. The directions of development of small and medium enterprises in the chemical industry of leather and footwear sector are designedyesБелгородский государственный университе

Analog of Magnetoelectric Effect in High-Tc Granular Superconductors

We propose the existence of an electric-field induced nonlinear magnetization in a weakly coupled granular superconductor due to time-parity violation. As the field increases the induced magnetization passes from para- to dia-magnetic behavior. We discuss conditions under which this effect could be experimentally measured in high-temperature superconductors.Comment: REVTEX (epsf style), 1 PS figure; to appear in Europhysics Letter